clear() {
  display: block
  content: ''
  height: 0
  overflow: hidden
  clear: both
  visibility: hidden
}
center() {
  position: absolute
  left: 50%
  top: 50%
  transform: translate(-50%, -50%)
}
// 单行省略
ellipsis() {
  overflow: hidden
  text-overflow: ellipsis
  white-space: nowrap
  word-break: break-all
}
// 多行省略
clamp(column) {
  word-spacing: -3px
  letter-spacing: 0px
  word-wrap: break-word
  word-break: break-all
  line-height: 20px
  overflow: hidden
  text-overflow: ellipsis
  white-space: normal
  display: -webkit-box
  -webkit-box-orient: vertical
  -webkit-line-clamp: column
}
// 动态设置
mval = 5 10 15 20 25 30 35 40
for val in mval {
  {'.pt-' + val} {
    padding-top: unquote('' + val + 'px')
    webkit-box()
  }
  {'.pr-' + val} {
    padding-right: unquote('' + val + 'px')
    webkit-box()
  }
  {'.pl-' + val} {
    padding-left: unquote('' + val + 'px')
    webkit-box()
  }
  {'.pb-' + val} {
    padding-bottom: unquote('' + val + 'px')
    webkit-box()
  }
  {'.ps-' + val} {
    padding: unquote('' + val + 'px')
    webkit-box()
  }
  {'.plr-' + val} {
    padding-left: unquote('' + val + 'px')
    padding-right: unquote('' + val + 'px')
    webkit-box()
  }
  {'.ptb-' + val} {
    padding-top: unquote('' + val + 'px')
    padding-bottom: unquote('' + val + 'px')
    webkit-box()
  }
}
for val in mval {
  {'.mt-' + val} {
    margin-top: unquote('' + val + 'px')
  }
  {'.mr-' + val} {
    margin-right: unquote('' + val + 'px')
  }
  {'.ml-' + val} {
    margin-left: unquote('' + val + 'px')
  }
  {'.mb-' + val} {
    margin-bottom: unquote('' + val + 'px')
  }
  {'.ms-' + val} {
    margin: unquote('' + val + 'px')
  }
  {'.mlr-' + val} {
    margin-left: unquote('' + val + 'px')
    margin-right: unquote('' + val + 'px')
  }
  {'.mtb-' + val} {
    margin-top: unquote('' + val + 'px')
    margin-bottom: unquote('' + val + 'px')
  }
}
